The present invention relates to molded; i.e. pressed, articles based on pyrogenically produced zirconium dioxide, the method for their preparation and their use as catalyst-carriers or catalysts.
Pyrogenically produced oxides are characterized by their exceedingly fine-particulate nature and their correspondingly high specific surfaces, their very high purities, spherical particle shapes and the lack of pores. On account of these properties, pyrogenically produced oxides are becoming increasingly significant as carriers for catalysts (D. Koth, H. Ferch, Chem. Ing. Techn. 52, 628 [1980]).
Pyrogenically produced zirconium dioxide is known. It is described in the German patent 36 11 449 Degussa AG). The properties, characteristics and composition thereof including impurities present therein are well known in the art.
However molded articles made of pyrogenically produced zirconium oxide are not known.
Because as a rule such pressed articles are used as catalysts or as catalyst-carriers, it is the object of the invention to provide molded, or pressed articles from pyrogenically produced zirconium dioxide which can be used in catalytic procedures.